1. Field of the Invention
The present invention relates to a slot apparatus, which allows the bare-dies to be attached on the slot apparatuses for a programmable multi-chip module or a high-density multi-layer printed circuit board.
2. Description of the Related Arts
Portable systems design and add-on cards have stringent limits on low-power and small-size constraints. A Multi-Chip Module (MCM) is a device in which several bare-dies are attached to a single substrate and then packaged as a small-size and low-power system. Furthermore, MCM packaging technology used in electronic systems translate the semiconductor speed into system performance, but low-power and high-density MCMs are expensive to fabricate and usually require weeks of engineering effort for system prototyping and product verification. The engineering delay in designing and fabricating such MCMs become unacceptable in today""s competitive market. The needs of quick turnaround time, high product yield, and low cost have led to the development of another approach, called Programmable Multi-Chip Module (PMCM).
This PMCM technology provides the designers with a pre-characterized MCM substrate and some programmable interconnections such that they can generate a fast prototyping or a final consumer product in a short time. The advantages of PMCM are that the field programmable technology can reduce product development cycle and NRE (Non-Recurrence Engineering) cost, while MCM technology can achieve low power and small size.
This PMCM substrate consists of an array of slot apparatuses for bare-dies attachment and Field Programmable Interconnect Chips (FPICs) for MCM substrate routing. Each bare-die pad is connected via a metal wire to a pad of the FPIC, and net routing is accomplished by programming the FPICs. Aptix and I-Cube are both well-known FPIC manufacturers.
FIG. 1 illustrates a programmable multi-chip module (PMCM) 10 according to the prior art. The PMCM 10 includes a substrate 12, a plurality of slot apparatuses 14 disposed on the substrate 12, and a plurality of bare-dies 16 attached on slot apparatuses 14. A plurality of pads 18 of PMCM 10 is disposed around the near-edge area of the substrate 12. A plurality of FPICs 20 is disposed on the substrate 12 and is located around the corresponding slot apparatuses 14 to interconnect the plurality of pads on the slot apparatuses 14 and the plurality of pads 18 on the PMCM. Each of the bare-die 16 is attached on one slot 14 using the wire bonding technology and is connected to one pad (not shown) on the slot apparatus 14. Each pad of slot apparatuses 14 is connected via a metal wire to one of the FPIC pads 20.
According to the prior art, each slot 14 on the PMCM 10 only accommodates one single bare-die 16. The number of bare-dies 16 disposed on the PMCM 10 is the same as the number of slot apparatuses 14 available. That is, the PMCM 10 of the prior art does not allow a flexible arrangement of the bare-dies 16. Furthermore, once the slot 14 is designed, the number of pads of a bare-die attached on the slot is limited by constraint. It is not feasible to apply the PMCM 10 of the prior art when a plurality of bare-dies 16 with different sizes and with different pad numbers is to be disposed on the PMCM 10.
To solve the aforementioned problems, the present invention discloses a slot apparatus on a PMCM. The purpose of these flexible slot apparatuses is aimed at attaching bare-dies 16 with different sizes and with different pad numbers on a PMCM 10 in different combinations. The slot apparatus of the present invention includes a plurality of the first-slot-modules to attach to at least one bare-die. Each slot pad is connected via a substrate metal wire to one of the FPIC pads, and the net routing is accomplished by programming the FPICs.
According to the present invention, a PMCM substrate with the slot apparatuses can provide a fast-built and low-cost prototyping system.